1. Field of Invention
This invention relates to a tandem seat assembly for an ultra light aircraft which generally has an empty weight of less than 254 pounds.
2. Description of Prior Art
Ultra light aircraft, which are not certified by the Federal Aviation Administration, are a class of aircraft which evolved from the hang glider. The hang glider is a non-powered ultra light glider that is controlled by one person shifting his weight in a type of harness or support suspended beneath the glider. An ultra light aircraft is essentially a hang glider in which a seat and landing gear replaces the harness. Also, a small engine and propeller have been added to provide a propulsive force, along with rudimentary aircraft and engine controls. Ultra light aircraft are used for sport and recreational purposes only.
However, since an ultra light aircraft has only one seat, all flight training must be performed on the ground. Many persons now flying ultra lights do not have any hang glider or aircraft flying experience. Instead they must rely solely on ground training, wherein the first flight is a solo flight. This creates a great danger to the pilot and others and can damage the aircraft as well as property on the ground.
Several attempts have been made to provide ultra light flight training. However, all prior designs involve a specific training aircraft with side by side seating. The known manufacturers of these side by side seating aircraft are Hummingbird, Rotec Engineering Inc. and Eipper. The side by side seating has proved to be less than successful due to the high drag caused by increased frontal area in addition to lateral instability resulting when only one person attempts to fly the aircraft.
The Army is presently evaluating a two seat ultra light aircraft in a side by side configuration. The present invention would give the Army a low drag configuration for dual seat operation. The Army's projected use is for surveillance, parachuting, mapping and flight training.
The construction of an ultra light aircraft requires a modern vehicle that is unlike conventional aircraft. The ultra light aircraft is normally constructed entirely of welded tubes or metalic members generally of high strength light weight steel that is usually welded together to form load carrying structures. Ultra light aircraft fuselages have no covering or skin, which exposes the pilot creating drag. Only the wings and tail surfaces are covered. Every attempt is made to save weight and minimize drag. Therefore, the largest drag item is the frontal area of the pilot.
Side by side seating produces large amount of drag since it is the frontal area of two pilots. In addition, it would be totally impractical to convert a single seat aircraft into a side by side for training purposes. It would require an engine substantially more powerful and a resulting weight increase to overcome the increased drag. However, a tandem seat for an ultra light aircraft will produce about the same frontal area drag as a single seat ultra light aircraft and require about the same power for flight.
It should be noted that since there is no skin or covering on the aircraft, all of the load is carried by the tubular members.
The single seat of an ultra light aircraft is usually made removable for maintenance and is not a load carrying member. Therefore, the present invention is limited to ultra light aircraft construction that allows the removal of a single seat without disrupting the integrity of load carrying members.
The novel features which are believed to be characteristics of the invention, both as to its organization and its method of operation, together with further objects and advantages thereof, will be better understood from the following description in connection with the accompanying drawings in which a presently preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for purposes of illustration and description only, and are not intended as a definition of the limits of the invention.